Will a good tune up help performance alot ?? Cause when I bought my car a year ago with 90K on it I dont know if he changed the plugs yet. The car get great gas milage but just really s*cks on the performance level...The ECU didnt detect any codes, so thats all good...Im at 104K now, do you think I should change the plugs alittle early or wait to 120K ?? thanks guys

Im gonna do the Fuel Filter right away though and see if that makes a difference

 

Well, if you got the car with 90k and you don't know if they have ever been changed I would say pull them out and visually inspect the plugs. If they look worn go ahead and change them. It won't hurt anything and you might even benefit from it.